1. Field of the Invention
The present invention relates to a machine and a process for formation of a continuous composite tape of laminated sheet material, in particular porous paper, and translucent material, in particular transparent film, for the production of wrappings for food products, including hot ones, as well as the tape and wrapping thus obtained.
The implementation modes according to the present invention of forming such a continuous composite tape provide the application of glue along preferred areas of the tape, so as to obtain a uniform thickness and allow the tape to be re-wound onto a spool without problems caused by the overlapping of the various layers one on the other, as well as to avoid intimate contact of the food product being inserted with the glue.
The composition of a continuous composite tape according to the present invention is such as to allow both transpiration of the product introduced during packing, and visibility of said product when on display. The bag-type wrapping formed starting from said continuous tape is also characterized by improved closure after introduction of the product, and also improved transportability along the food product insertion line, even when the food product in question is a hot one.
A preferred use of continuous composite tapes according to the present invention relates to the production of wrappings particularly suited to the introduction of bakery products, and in particular bread. These products, unlike what can be seen in present packing systems (Kraft paper, micro-perforated film, plastic film, paper of various types), if introduced while still hot, are thus able to preserve both their fragrance and their organoleptic properties.
2. Description of the Prior Art
Machines and processes are known for the production of wrapping for bakery products. However, neither these machines nor the processes according to the prior art provide for glue application along preferred areas of the continuous composite tape forming the wrapping, and they do not provide the production in roll form of a continuous composite tape allowing the packing of hot foot products.
Also known, Italian utility model application RM-93-U-000031, is a packing comprising a bag wrapper with folded sides made of a specific type of porous paper that has the characteristic of allowing dry food products to be introduced into it at high temperatures of up to 100.degree., and of allowing the exchange of gas between the inside and the outside of said packing, in order to preserve the organoleptic properties of the products placed therein.
This packing, however, is sealed using known methods, and it is not provided that said scal be formed by tempering a layer of glue applied along preferred areas within the packing itself.